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温度

0 °C

A solution of 91 g (510 mmol) N-3-pyridylpivalamide and 230 ml (1.53 mol) N,N,N′,N′-tetramethylethylenediamine under argon in 2000 ml tetrahydrofuran was cooled in a dry ice bath to −78° C. Within 1 h, 153 ml (1.53 mmol) of a 10 N n-butyllithium solution in hexane were added dropwise. The reaction mixture was stirred at 0° C. for additional 2 h. After cooling again to −78° C., 380 g (1.5 mol) iodine dissolved in 300 ml tetrahydrofuran were added dropwise during 1.5 h. The dry ice bath was removed and the reaction mixture was allowed to warm up to room temperature overnight. Stirring was continued and 1000 ml water and 1000 ml saturated sodium thiosulfate pentahydrate solution were added. The aqueous layer was separated and extracted twice with 800 ml ethyl acetate. The combined organic layers were dried (magnesium sulfate) and evaporated. Chromatographical filtration gave 75 g (48%) of the title compound as brown crystals.

1. temperatureAfter cooling again to −78° C.
2. additionwere added dropwise during 1.5 h
3. customThe dry ice bath was removed
4. temperatureto warm up to room temperature overnight
5. stirringStirring
6. addition1000 ml water and 1000 ml saturated sodium thiosulfate pentahydrate solution were added
7. customThe aqueous layer was separated
8. extractionextracted twice with 800 ml ethyl acetate
9. dry with materialThe combined organic layers were dried (magnesium sulfate)
10. customevaporated
11. filtrationChromatographical filtration